My ranking & explanations.
1. Tomb of Annihilation - I am currently playing this and our party is in the final dungeon. I have not read the adventure; will do so once we finish it. Great story, great characters, plenty of variety, wonderful locations. Tomb of the Nine Gods is the best dungeon I've seen in 5E with the possible exception of Castle Ravenloft. Adventure's only weakness is the beginning; I would benefit from a railroad kickstart a la Death House to get to level 2 or 3 before opening up. Port Nyanzaru is the weakest part of the adventure.
2. Lost Mine of Phandelver - Have run this twice as a DM. As others have stated, pretty much perfect for its intended purpose as a gateway drug for this edition. It has its flaws but they are very easy for a DM to fix/improve upon.
3. Curse of Strahd - Have run as a DM. A classic; preserves all the strengths of the original and improves on it.
4. Out of the Abyss - Have read. Some of the best set piece encounters I've ever seen. Valuable as an Underdark source book even if you never run it as an adventure. Suffers from disorganized presentation; not at all as user-friendly as later adventures.
5. Ghosts of Saltmarsh - Have read. 2 great adventures, 1 good one, 2 mediocre ones, and 2 bad ones, and a TON of great setting material and resources Danger at Dunwater and the Final Enemy should have been re-imagined instead of re-printed.
6. Dragon of Icespire Peak - Currently running as DM. For its intended purpose, this is inferior to LMoP and does not provide a complete sense of the game in the way that LMoP does. Contains some fun scenarios. Some curiously flawed and badly balanced encounters considering the edition was mature, seasoned, and well-tested when it was published. Good if you're looking for fun, mostly combat-oriented serial adventures without much deep thought required. The three follow-up adventures on DNDBeyond aren't very good.
7. Tales from the Yawning Portal - Have run some as DM, read the rest. The most fun and playable at the table for most 5E players will be the two 3E adventures. The 1E stuff mostly does not hold up imo; adventures have evolved for the better.
7. Waterdeep: Dragon Heist - Have read. Ambitious but quite flawed. Feels like it needed more time in development. Ends with a whimper. Some fun set piece encounters along the way, and easy to run for the most part.
8. Horde of the Dragon Queen - Have read. Not quite as horrible as its rep, but not very good. Fairly easy to prep & run.
9. Storm King's Thunder - Have run parts of it as DM. I don't see what others love about this one. A huge hassle to prep, and I can't see where it's worth the effort to do so. Weak story, and the set pieces aren't as good as many of the other books offer.
Hard to judge:
Waterdeep: Dungeon of the Mad Mage. This is boring as hell to read, but might be fun at the table.
Haven't read or played:
Rise of Tiamat
Princes of the Apocalypse
Baldur's Gate: Descent Into Avernus
Hunt for the Thessalhydra
Rick & Morty
Acq Inc
1. Tomb of Annihilation - I am currently playing this and our party is in the final dungeon. I have not read the adventure; will do so once we finish it. Great story, great characters, plenty of variety, wonderful locations. Tomb of the Nine Gods is the best dungeon I've seen in 5E with the possible exception of Castle Ravenloft. Adventure's only weakness is the beginning; I would benefit from a railroad kickstart a la Death House to get to level 2 or 3 before opening up. Port Nyanzaru is the weakest part of the adventure.
2. Lost Mine of Phandelver - Have run this twice as a DM. As others have stated, pretty much perfect for its intended purpose as a gateway drug for this edition. It has its flaws but they are very easy for a DM to fix/improve upon.
3. Curse of Strahd - Have run as a DM. A classic; preserves all the strengths of the original and improves on it.
4. Out of the Abyss - Have read. Some of the best set piece encounters I've ever seen. Valuable as an Underdark source book even if you never run it as an adventure. Suffers from disorganized presentation; not at all as user-friendly as later adventures.
5. Ghosts of Saltmarsh - Have read. 2 great adventures, 1 good one, 2 mediocre ones, and 2 bad ones, and a TON of great setting material and resources Danger at Dunwater and the Final Enemy should have been re-imagined instead of re-printed.
6. Dragon of Icespire Peak - Currently running as DM. For its intended purpose, this is inferior to LMoP and does not provide a complete sense of the game in the way that LMoP does. Contains some fun scenarios. Some curiously flawed and badly balanced encounters considering the edition was mature, seasoned, and well-tested when it was published. Good if you're looking for fun, mostly combat-oriented serial adventures without much deep thought required. The three follow-up adventures on DNDBeyond aren't very good.
7. Tales from the Yawning Portal - Have run some as DM, read the rest. The most fun and playable at the table for most 5E players will be the two 3E adventures. The 1E stuff mostly does not hold up imo; adventures have evolved for the better.
7. Waterdeep: Dragon Heist - Have read. Ambitious but quite flawed. Feels like it needed more time in development. Ends with a whimper. Some fun set piece encounters along the way, and easy to run for the most part.
8. Horde of the Dragon Queen - Have read. Not quite as horrible as its rep, but not very good. Fairly easy to prep & run.
9. Storm King's Thunder - Have run parts of it as DM. I don't see what others love about this one. A huge hassle to prep, and I can't see where it's worth the effort to do so. Weak story, and the set pieces aren't as good as many of the other books offer.
Hard to judge:
Waterdeep: Dungeon of the Mad Mage. This is boring as hell to read, but might be fun at the table.
Haven't read or played:
Rise of Tiamat
Princes of the Apocalypse
Baldur's Gate: Descent Into Avernus
Hunt for the Thessalhydra
Rick & Morty
Acq Inc